Additional Features:

• Broad band noise signal: 5 Hz to 5 MHz
• Uniform spectrum level
• Useful in noise and vibration testing of mechanical and electrical systems
• Upper frequency cutoff can be set at: 20 kHz, 500 kHz, or 5 MHz
• Output level is controlled by a 4-step attenuator with 20 dB steps and a continuously variable control providing a calibrated, metered output from <30 µV to 3 V (depending on filter setting
• Audio spectrum level uniformity is rated at ±1 dB
• A 1521B Level Recorder can be attached to give continuous records of level versus frequency

The General Radio 1390B Random-Noise Generator provides a high level of electrical noise at its output terminals. This type of signal is useful in room acoustic measurements, loudspeaker and microphone tests, psychoacoustic tests, filter tests, crosstalk measurements for multichannel carrier systems, calibration checks on recording systems, modulation of signal generators and test oscillators, tests of RMS response of meters, observation of resonance in systems, electrical averaging of resonant responses; and comparisons of effective band width. A pair of these generators can be used as signal sources for demonstration of various degrees of correlation, possible errors of random sampling, and other concepts of statistical theory.